HTC One M8 AT&T – Flash Error – PLEASE HELP!!


I am trying to flash a phone back to stock firmware with XTC 2 Clip Flash Method. I renamed filed to 0P6BIMG just like tutorial says but get error when trying to flash the file. I downloaded the AT&T stock firmware from your website.

The phone I am flashing has some Google Custom ROM on it. The Bootloader is "Unlocked". S-OFF. Super CID.

When I go to flash the file, I get this error…

Starting flash process…
Execution time is 2734(ms)
sending ‘zip’… (57600 KB) OKAY
writing ‘zip’… FAILproject does not have sa key to decrypt rom
FAILED (remote: project does not have sa key to decrypt rom)
Flash process completed.

Can anyone explain to me how to fix this issue or why it is happening. I even tried to flash a Stock RUU and still am getting error. Why is this I thought you could flash any ROM with S-OFF.

Please Help!!